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Electronics => Electronics => Topic started by: Builder1 on September 16, 2008, 07:33:55 PM

Title: DC to DC Converters
Post by: Builder1 on September 16, 2008, 07:33:55 PM
Hello All,
I have a few questions regarding dc to dc converts. Has anyone ever used one and how are these devices used? Also what does an average converter cost? Thank you in advance for you help.
Title: Re: DC to DC Converters
Post by: ArcMan on September 17, 2008, 09:16:04 AM
A DC-to-DC converter is used to produce a galvanically isolated voltage supply of a value you don't already have in your system.  For example, if you have a 5VDC system and need to generate +/- 10VDC signals, you can use a DC-to-DC converter to produce the +10VDC and -10VDC.  (I know - You can actually use a charge-pumped MAX232 chip to do this, too - but it's just an example).
Title: Re: DC to DC Converters
Post by: Rebelgium on September 17, 2008, 12:14:46 PM
It's a circuit that converts one DC voltage to another DC voltage (higher = boost, lower =buck).
You can make it yourself using an IC and some external components. That is the cheapest way, another way is to buy an off the shelf module...
Search for shops that sell them to get a price.

A DC-to-DC converter is used to produce a galvanically isolated voltage supply of a value you don't already have in your system.  For example, if you have a 5VDC system and need to generate +/- 10VDC signals, you can use a DC-to-DC converter to produce the +10VDC and -10VDC.  (I know - You can actually use a charge-pumped MAX232 chip to do this, too - but it's just an example).

It's not Galvanically isolated. :)
Title: Re: DC to DC Converters
Post by: ArcMan on September 17, 2008, 02:43:04 PM
It's not Galvanically isolated. :)

My statement is incorrect as a general statement.  I was thinking of magnetic DC-to-DC converters, which are galvanically isolated.
Title: Re: DC to DC Converters
Post by: Builder1 on September 17, 2008, 07:27:57 PM
Hello Everyone,
Thank you all for your response, I have just two questions remaining .

1) Can one build a dc to dc converter to decrease or increase a voltage to a different voltage no matter how small or large it is or is there a limit to how small or large the increase or decrease can be?

2)Is there a website that has materials on how to do this?
 Thank you again for responding.
Title: Re: DC to DC Converters
Post by: Webbot on September 17, 2008, 08:30:31 PM
Simple point - but dont forget that you dont get something for nothing.

So if the convertor is 100% effiicient (unlikely) then power in  = power out.

Power = Amps x Volts

So if your convertor is outputing twice the voltage then it will need twice the current on the input.

ie if output is 10v at 1 amp then output power is 10x1=10 watts
So if input voltage is 5v its will draw a current of: Amps = Power / Volts = 10 Watts / 5v = 2 amps.
Title: Re: DC to DC Converters
Post by: TrickyNekro on September 18, 2008, 12:45:06 AM
Get a TC7662 perfect for DC to DC step up/down...
There is also a newer version TC962.... same but more improved, didn't get to see the datasheets...

Regards, Lefteris
Greece